广东南澳岛次生林的群落结构分析

Community structure of three secondary forests in Nan'ao Island, Guangdong

研究了广东南澳岛的 3个次生林群落的物种结构、水平结构、垂直结构和组织水平结构。这 3个次生林的植物物种数为 1 7～ 3 0种 ,主要种类为鸭脚木、假苹婆、土蜜树、降真香等 ,这些树种与大陆同地带的鼎湖山、白云山次生林群落的种类具相似性。这些群落的高度为 9～ 1 2 m,可分为乔木、灌木和草本层 3个层次。乔木层的平均个体密度为 0 .5 4～ 1 .74株 /m2。群落的多样性指数为 2 .1 1～ 3 .0 2 ,均匀度 0 .5 4～ 0 .87,生态优势度 0 .1 2～0 .40。南澳岛的次生林群落是该岛乡土树种物种库的主要承载者 ,这些次生林对整个岛屿的物种库和生态系统多样性的形成和维持具有重要的作用。可充分利用海岛上残存的次生林缀块 ,通过建立人工廊道 ,从而形成缀块—廊道—基底格局 ,以利于整个海岛顶极群落的早日形成。文中还比较了南澳岛退化草坡、人工林和次生林群落的结构 ,并建议通过人工造林在退化草坡上恢复森林 ,对现有的人工林进行改造 ,继续保护和管理次生林。

The community structures of three secondary forests were analyzed in Nan'ao Island, Guangdong. The communities have 17～30 species in the plots, with dominant species Schefflera octophylla, Sterculia lanceolata, Acronychia pedunculata and Bridelia tomentosa. The height of the communities is form 9～12 meters, and they can be divided into tree layer, shrub layer and herb layer. The average density of tree layer of the communities is 0 54～1 74 individuls/m 2. The Shannon-Weiner index of diversity, evenness index, ecological dominance of the communities are 2 11～3 02, 0 54～0 87 and 0 12～0 40, respectively. The secondary forests are the carriers of the pool of species and are very important for sustaining the biodiversity in the Island. We can make full use of the secondary patches, construct artificial native species corridor, protect plantations, and establish climax in the Island at last. In addition, We compared the community structure of secondary forests with that of degraded hilly land and plantations.